Could you please help me to solve the following question? The answer seems $54,000 but my calculation is $46,000. How can I get $54,000? Please explain.

"LMN Company was organized on January 1, 2018. At the end of the first quarter (three months) of operations, the owner prepared a summary of its activities as shown below. What is net income?

Services performed for customers, $85,000, of which $15,000 remained uncollected at the end of the quarter.

Small service truck purchased at the end of the quarter to be used in the business for two years starting the next quarter: cost, $8,000 cash.

Operating expenses, $31,000, of which one-half remained unpaid at the end of the quarter."